Domestic appliance



June 13, 1967 F, E. LA FLAME 3,324,796

DOMESTIC APPLIANCE Original FiledMarch 26, 1965 5 Sheets-Sheet l INVENTOR.

June 13, 1967 F. E. LA FLAME DOMESTIC APPLIANCE 3 Sheets+8heet 2 Original Filed March 26, 1963 INVENTOR. Ema/r f: Za/Yame BY gp. (fl/W June 13, 1967 F. E. LA FLAME 7 3,324,796

DOMESTIC APPLIANCE 3 Sheets-Sheet 2- Original Filed March 26, 1963 INVENTOR. flank f. 10/702276 BY H16 ATTOR/VfY Patented June 13, 1967 3,324,796 DOMESTIC APPLIANCE Frank E. LaFlame, Dayton, Ohio, assignor to General Motors Corporation, Detroit, Mich, a corporation of Delaware Original application Mar. 26, 1963, Ser. No. 268,053, now Patent No. 3,244,105, dated Apr. 5, 1966. Divided and this application Feb. 1, 1966, Ser. No. 524,048

3 Claims. (Cl. 103-3) This application is a division of copending United States application, Ser. No. 268,053, filed Mar. 26, 1963.

This invention relates to fluid circulation systems for association with a fluid containing sump and more particularly to such systems having a plurality of pumps selectively operable to circulate fluid within the sump and to drain the sump.

In many plural pump arrangements suitable for association with a fluid containing sump, fluid is recirculated selectively within the sump by one of the pumps or drained therefrom by the other of the pumps. In such systems, it is desirable that the pumps be driven concurrently by a single motor. The pumps, preferably, are arranged or have means associated therewith to prevent the sump from being drained during periods of fluid recirculation. Furthermore, in cases where the drain pump communicates with a waste drain, it is desirable to have means associated with the pumping arrangement to prevent fluid from being withdrawn from the drain and pumped into the sump.

One problem with such plural pump arrangements has been that of eliminating the return of waste from the drain into the sump. Another problem is the fact that most pump assemblies are only adapted for use in a particular fluid containing sump.

A still further problem with such plural pump arrangements is that if fluid is trapped in the pumping chamber of the primary circulation pump when the sump is being drained, it will produce an undesired drag on the pump drive means and also create an undesirable noise level.

Another problem present in such plural pump arrangements is that matter will collect in the low point of the sump associated therewith. Furthermore, the location of the sump is usually relatively inaccessible and it is therefore diflicult to clean waste matter therefrom. This problem is especially true in dishwashers where the sump is often hidden beneath elaborate fluid distribution systems. Thus, food particles and the like that collect in the sump can be cleaned therefrom manually only by exerting a great deal of effort.

One object of the invention, therefore, is to provide an improved plural sump arrangement that will be suitable for draining fluid from and circulating fluid within many different types of fluid containing sumps.

Another object of the invention is to improve a plurality of pumps for association with a fluid containing sump by including means in association therewith for preventing fluid in a drain connected to the sump from returning to the sump after being pumped there-from.

A further object of the invention is to solve the problem of cleaning relatively inaccessible sumps, for example, fluid containing sumps in cleaning devices such as dishwashing apparatus, by providing means in association therewith for flushing the inner surface of the sump during periods in which the sump is being drained.

Another object of the present invention is to prevent a drain pump that is operated concurrently with a pump for circulating fluid in a sump from drawing fluid from a drain and returning it to the sump by negating the pumping head of the drain pump when the circulation pump is circulating fluid within the sump by the provision of means for venting a portion of the pumping chamber of the drain pump to atmosphere to effect a vacuum breaking check between the drain and the drain pump.

A further object of the invention is to provide an improved drain pump for association with a sump having means for filtering fluid passing thereto wherein the drain pump removes water from the sump while removing waste from the filter.

A still further object of the invention is to improve a plural pump arrangement for association with a fluid containing sump wherein one of the pumps circulates fluid from the sump and distributes it to a point remote therefrom and the other of the pumps concurrently tends to draw fluid from "a drain into the sump by providing check means in association with the drain pump to prevent the drain pump from drawing fluid from the drain and passing it into the sump with the check means serving to direct fluid from the drain pump as it draws fluid from the sump so as to flush matter from the inner surface of the sump during such drainage; and

Yet another object of the invention is to improve the combination of a primary circulation pump having a convoluted casing and a drain pump for association with a sump by including means in the primary circulation pump for draining the casing thereof during a first predetermined circulation of fluid within the casing to negate noisy operation of the pump and drag on its drive means during such circulation with said drain means being responsive to a second predetermined circulation of fluid Within the casing to prevent drainage therefrom.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings wherein a preferred embodiment of the present invention is clearly shown.

In the drawings:

FIGURE 1 is an elevational view of the invention in a domestic dishwasher cabinet;

FIGURE 2 is an enlarged view in vertical section taken along the line 22 of FIGURE 1;

FIGURE 3 is a top elevational view looking in the direction of arrow 3 in FIGURE 2;

FIGURE 4 is a view in horizontal section taken along the line 44- of FIGURE 2;

FIGURE 5 is a view in horizontal section taken along the line 5-5 in FIGURE 2;

FIGURE 6 is a view in vertical section taken along the line 6-6 of FIGURE 3; and

FIGURE 7 is a view in vertical section taken along the line 77 of FIGURE 3.

Referring now to the drawings, one embodiment is illustrated in FIGURES 1 through 3 as being associated with a dishwashing unit 10 having an outer casing 12 and a bulkhead 14 located Within the outer casing to divide it into an upper Washing compartment 16 and a lower machinery compartment 18.

The central portion of the bulkhead 14 is recessed to form a substantially conically shaped sump 20 for collecting fluid being circulated within the washing compartment 16. In the illustrated arrangement, the bottom of the sump 20 is formed by a slightly downwardly dished supporting plate 22 of an improved plural pump arrangement 24 for circulating fluid within the washing compartment 16 through a tubular distribution post 28 into contact with dishes or the like supported on racks (not shown) within the washing compartment, and for draining the sump following a washing operation into a looped drain 32.

Referring now more particularly to the construction of the fluid circulation system 24, FIGURES 2 through show a preferred embodiment of the present invention including a primary circulation pump 26 and a drain pump 30 and wherein the supporting plate 22 has the outer peripheral edge thereof inserted into an annular seal 34 carried by a radially inwardly turned edge 36 of the conically shaped sump 20. The primary circulation pump 26 is illustrated representatively in this embodiment of the invention as comprising an outer casing 38 secured by suitable means, such as screws 39, centrally of the upper surface of the support-ing plate 22 so as to be located within the sump 20. The outer casing 38 has a generally circular outer peripheral surface with a plurality of circumferentially spaced inlet ports 40 located adjacent the bottom thereof with one of such ports being illustrated in FIGURE 2. Each of the inlet openings 40 is separated from an adjacent opening 40 by a radially inwardly tapered divider or post 42 that serves as a means for directing fluid from a point exteriorly of the outer casing 38 into the interior thereof. Each of the inlet openings 40 communicates with an arcuate depression 44 formed by the slightly dished supporting plate 22 (see FIGURE 2).

The primary circulation pump 26 further includes a rotatable member 46 having a plurality of turbine blades 48 directed radially outwardly thereof to a point adjacent the inside surface of the radially inwardly tapered posts 42 with the outer surface of the rotatable member 46 and the inwardly facing surfaces of the radially inwardly tapered posts serving as a pumping chamber 49 from whence fluid is forced by the turbine blades 48 on rotation of the rotatable member 46 upwardly thereof within the outer casing 38. A plurality of circumferentially spaced curved blades "50 located above the turbine blades 48 have the radially outer bottom edges thereof carried by the upper edge of the posts 42 and their radially inner edges connected to a connoidal shaped hub 52 for locating it centrally of the casing 38 t0 define a plurality of flow passageways 54 therethrough for straightening the fluid pumped upwardly and outwardly of the casing 38 by the turbine blades 48. The straightened fluid flow is then passed into a suitable distribution means, such as the post 28, to a point of distribution remote from the sump where it is directed under pressure against the items to be washed.

The drain pump 30 is illustrated representatively as including a casing formed by a centrally located downwardly directed bulged portion 56 formed in the supporting plate 22 having the upper surface thereof formed by a head plate 58 supported by the supporting plate 22 at grooves 60 located therein with the head plate 58 serving to seal against fluid leakage between the primary circulation pump 26 and the drain pump 30 and to form, in conjunction with plate 22, a pumping chamber 61 within the pump 30.

In the illustrated arrangement, an inlet passageway 63 to the drain pumping chamber 61 is formed in the supporting plate 22 in communication with the low point in the arcuate depression 44 therein. A radially outer portion of the head plate 58 overlying the inlet 63 has a plurality of spaced fingers 65 extending downwardly therefrom serving to direct flow from the depression 44 into the inlet 63 and to prevent the entrance of large objects therein. The inlet passageway 63 further prevents objects 4 from entering the pumping chamber 61 by being formed in an S-shape, as best shown in FIGURE 5. An outlet passageway 67 from the chamber 61 is formed in the plate 22 to communicate with the drain 32, as best shown in FIGURE 6.

The primary circulation pump 26 and drain pump 30 are operatively interrelated by means of an elongated tubular shaft 62 having one end thereof directed through a central opening in the head plate 58 so as to support the rotatable member 46 in the primary circulation pump 26, with the member 46 being secured thereto by means of suitable means such as a threaded bolt 63. The opposite end of the tubular shaft 62 is located within the drain pump casing 56 and is formed as a fluid displacement member 64 having radially outwardly directed blades 66 circumferentially spaced around a radially outwardly di rected edge 68 thereon at staggered points thereabove and therebelow. A hub 70 formed on the member 64 below the radial blades 66 is internally threaded to threadably engage a threaded end of a shaft 72 of a suitable reversi= ble drive means, such as a reversible electric motor 74, suspended beneath the supporting plate 22 by suitable means such as bolts 76 directed therethrough. The shaft 72 of the motor 74 hence is connected directly to both the rotatable member 46 of the primary circulation pump 26 and the fluid displacement member 64 of the drain pump 30 so that they will rotate in the same direction. Leakage along the outer periphery of the tubular shaft 62 and drive shaft 72 is prevented by a seal 78 supported in the top of the rotatable member 46 in surrounding sealing engagement with the tubular shaft 62 and by a seal 80 supported in a central recess 82 formed in the pump casing 56 with said seal 80 being located in surrounding sealing engagement with the outer peripheral surface of the hub 70- on the fluid displacement member 64.

To eifect selective circulation of fluid from the sump 20 to a distribution point remote therefrom by means of the primary circulation pump 26 and drainage of the sump by drain pump 30 the fluid displacement assemblies of the primary circulation and drain pumps are arranged to circulate fluid through the respective pumps in opposite directions between the inlets and outlets thereof depending upon the direction of rotation thereof as determined by the reversible motor 74. More particularly, each of the pumping chambers 49, 61 formed in the primary circulation and drain pumps 26, 30, respectively, are arranged about the fluid displacement assemblies 46, 64 thereof, as best illustrated in FIGURES 4 and 5, such that when the motor 74 is rotated in a clockwise direction as viewed in FIGURES 4 and 5, fluid is drawn by the primary circulation pump 26 through the inlet openings 40 thereof and forced out the outlet thereof through the tubular distribution post 28 during a predetermined washing cycle or the like. It will be appreciated that the fluid displacement member 64 of the drain pump concurrently rotates in a clockwise direction and as a result will draw fluid from the looped drain 32 and force it into the sump 20. The return of waste fluid present in the drain 32 into the sump during the primary circulation operation is undesirable obviously since such fluids will be recirculated by the primary circulation pu-mp 26 and consequently will contaminate the whole washing compartment 16.

Upon counterclockwise rotation of the motor 74, the primary circulation pump 26 will draw fluid from the tubular distribution post 28 and discharge it through the inlet openings 40 into the sump concurrently while the drain pump 30 draws fluid from the sump through the inlet passageway 63 thereof and discharges it through the outlet passageway 67 into the looped drain 32. In other words, circulation of fluid in the washing compartment 16 by the primary circulation pump 26 and drainage of fluid from the sump by the drain pump 30 are obtained selectively by reversing the operation of the motor 74. The provision for such selective operation is needed since drainage of the sump 20 by the drain pump 30 during circulation of fluid within the sump by the primary circulation pump 26 would eventually drain all of the fluid from the washing compartment 16 and hence limit the washing cycle or the like in an undesirable manner.

While the above-described arrangement permits a desired retention of fluid within the sump 20 during the washing cycle or the like, it presents the problem of contaminating the washing compartment 16. One suggested solution to this problem is to provide a one-way check valve in the looped drain 32 adjacent the outlet from the drain pump with the one-way check valve preventing flow therefrom back into the sump 20. Such check valves, however, tend to leak after a period of use and the problem is again present.

Therefore, in accordance with certain of the principles of the present invention, a portion of the drain pumping chamber 61 is vented to atmosphere by vacuum breaking means 85 including a hollow protuberance 90 formed in the outer casing 38 of the primary circulation pump 26 and an elongated tubular element 92 located within the protuberance 90 and held therein by portions of the inside surface thereof so that the upper end of element 92 is spaced from the top of the protuberance 90, as best illustrated in FIGURES 6 and 7. An opening 94 in the upper end of protuberance 90 communicates with the atmosphere above fluid in the sump 20 and the lower end of the tubular element 92 communicates with a passageway 95 in the head plate 58 into the outlet passageway 67 of the drain pump 30. Thus, the outlet of the drain pump 30 is maintained at atmospheric pressure during periods in which pump 30 tends to draw fluid from the looped drain 32 and force it into the sump, and thus the pumping head of the drain pump 30 is negated eflectively during such periods to avoid thereby the problem of forcing waste fluids into the sump 20 and the attendant problems of contaminating the washing chamber 16.

The protuberance 90 further includes an opening 96 located adjacent the lower portion of the outer casing 38 into which fluid from the sump 20 will flow, but the vertically extending tubular element 92 has sufficient height to prevent by-passing fluid between the opening 96 and the passageway 95 and an air space is maintained thereby at the upper end of protuberance 90 to produce the above-described venting of the outlet passageway 67 of the drain pump 30 during periods in which it might tend to draw waste fluid from drain 32.

In accordance with certain other of the principles of the present invention the hollow protuberance 90 is filled with fluid from the sump 20 when the drain pump 30 draws fluid from the sump 20 since during this operation the fluid in the outlet passageway 67 of the drain pump 30 is maintained under pressure and is forced into the protuberance 90 and directed outwardly through the openin'gs 94, 96 therein. The opening 96 is relatively larger in cross sectional area than the opening 94 from the protuberance 90, and hence the greatest portion of the flow through the protuberance 90 occurs therethrough. The opening 96 is, as best ilustrated in FIGURE 3, faced substantially tangentially to the curved outer periphery of the casing 38 and furthermore is substantially tangential to the curvature of the inner surface of the sump 20 and the support plate 22. Accordingly, fluid pumped through the protuberance 90 will be directed through the arcuate depression 44 in the supporting plate to effectively flush waste matter deposited therein toward the inlet passageway 63 of the drain pump 30 for removal from the sump 20.

Such an automatic flushing action prevents a buildup of waste materials in the sump that would tend to cause a condition therein that is unsightly or unsanitary, and therefore reduces the need for manually cleaning what is in many cases a relatively inaccessible portion of a domestic appliance or the like.

Another feature of the above-described embodiment of the invention is the use of the turbine or mixed flow type of pump 26 as the primary circulation pump. In the illustrated arrangement the blades 48 of the pump have an angle of attack that will cause reverse flow through the pump during drainage of the sump 20. This reverse flow feature is desirable in many dishwashing arrangements since pumping fluid into the washing compartment 16 during drainage of the sump 20 may tend to cause Waste matter to be redistributed upon dishes supported therein. In other dishwasher arrangements, however, a manufacturer may provide means for filtering the water being circulated by the primary circulation pump. In this case the fluid in the sump is relatively clean and it can be used for washing the inside surface of the cleaning compartment during the draining cycle so that any waste mat ter will be removed therefrom and pumped by the drain pump from the unit. Accordingly, many manufacturers desire a unidirectional flow from the outlet of the primary circulation pump both during recirculation of the fluid during the washing cycle and during the drainage cycle whereby fluid is drawn from the sump by the primary circulation pump and forced through the distribution system against the dishes supported in the washing compartment and against the inner surface of the washing compartment. In the above-described embodiment such unidirectional flow can be obtained through the outlet passageways 54 and fluid distribution post 28 by changing the angle of attack of the blades 48 of the mixed flow or turbine pump 26 until there is a positive flow upwardly thereof during both directions of rotation thereof. In other words, in the above-described arrangement the primary circulation pump will have a reverse direction of fluid flow therethrough or be unidirectional, depending upon the desires of the particular manufacturer, merely by changing the angle of attack of the turbine blades 48. Accordingly, the plural pump arrangement 24 will be suitable for draining fluid from and circulating fluid within many different types of dishwashers without requiring any major modifications in the primary circulation pump thereof.

While the embodiment of the present invention as herein disclosed constitutes a preferred form, it is to be understood that other forms might be adopted.

What is claimed is as follows:

1. In a dishwasher, the combination of, a water container having a sump and a drain, a supporting plate connected to and forming a portion of the bottom of said sump, fluid circulating means including an elongated tubular open-ended pump casing on said plate forming a pumping chamber having an inlet communicating with said sump and an outlet communicating with a point of distribution above said sump, a mixed flow turbine impeller within said casing, a reversible electric motor operable in a first direction during a washing cycle and in a reverse direction during a drain cycle, means for connecting said motor to said mixed flow impeller, said mixed flow impeller drawing fluid from said sump through said casing to the point of distribution during said washing cycle drain pump means supported on said water container below said pump casing, said drain pump means including a second casing forming a pumping chamber having an inlet in communication with said sump and an outlet in communication with said drain, said tubular open-ended casing overlying said drain pump means and having all portions of the outer surface thereof spaced a substantial distance from said water container to allow free return of fluid to said sump, an impeller in said pumping chamber of said drain pump means connected to said motor to be driven thereby during the drain cycle to pump fluid from said sump into said drain, said inlet in said drain pump means underlying said inlet to said pump casing, said mixed flow turbine impeller during the drain cycle producing a second circulation of fluid from said sump through said casing to said point of distribution whereby fluid in said sum-p freely flows therefrom into said inlet of said drain pump means during the drain said pumping chamber to prevent the entrance of large objects from said sump into said drain pumping chamber.

References Cited UNITED STATES PATENTS 4/1963 Hardy et a1. 103-3 4/1966 LaFlame et a1. 103-3 DONLEY J. STOCKING, Primary Examiner.

MARTIN P. SCHWADRON, Examiner.

W. J. KRAUSS, Assistant Examiner. 

1. IN A DISHWASHER, THE COMBINATION OF, A WATER CONTAINER HAVING A SUMP AND A DRAIN, A SUPPORTING PLATE CONNECTED TO AND FORMING A PORTION OF THE BOTTOM OF SAID SUMP, FLUID CIRCULATING MEANS INCLUDING AN ELONGATED TUBULAR OPEN-ENDED PUMP CASING ON SAID PLATE FORMING A PUMPING CHAMBER HAVING AN INLET COMMUNICATING WITH SAID SUMP AND AN OUTLET COMMUNICATING WITH A POINT OF DISTRIBUTION ABOVE SAID SUMP, A MIXED FLOW TURBINE IMPELLER WITHIN SAID CASING, A REVERSIBLE ELECTRIC MOTOR OPERABLE IN A FIRST DIRECTION DURING A WASHING CYCLE AND IN A REVERSE DIRECTION DURING A DRAIN CYCLE, MEANS FOR CONNECTING SAID MOTOR TO SAID MIXED FLOW IMPELLER, SAID MIXED FLOW IMPELLER DRAWING FLUID FROM SAID SUMP THROUGH SAID CASING TO THE POINT OF DISTRIBUTION DURING SAID WASHING CYCLE DRAIN PUMP MEANS SUPPORTED ON SAID WATER CONTAINER BELOW SAID PUMP CASING, SAID DRAIN PUMP MEANS INCLUDING A SECOND CASING FORMING A PUMPING CHAMBER HAVING AN INLET IN COMMUNICATION WITH SAID SUMP AND AN OUTLET IN COMMUNICATION WITH SAID DRAIN, SAID TUBULAR OPEN-ENDED CASING OVERLYING SAID DRAIN PUMP MEANS AND HAVING ALL PORTIONS OF THE OUTER SURFACE THEREOF SPACED A SUBSTANTIAL DISTANCE FROM SAID WATER CONTAINER TO ALLOW FREE RETURN OF FLUID TO SAID SUMP, AN IMPELLER IN SAID PUMPING CHAMBER OF SAID DRAIN PUMP MEANS CONNECTED TO SAID MOTOR TO BE DRIVEN THEREBY DURING THE DRAIN CYCLE TO PUMP FLUID FROM SAID SUMP INTO SAID DRAIN, SAID INLET IN SAID DRAIN PUMP MEANS UNDERLYING SAID INLET TO SAID PUMP CASING, SAID MIXED FLOW TURBINE IMPELLER DURING THE DRAIN CYCLE PRODUCING A SECOND CIRCULATION OF FLUID FROM SAID SUMP THROUGH SAID CASING TO SAID POINT OF DISTRIBUTION WHEREBY FLUID IN SAID SUMP FREELY FLOWS THEREFROM INTO SAID INLET OF SAID DRAIN PUMP MEANS DURING THE DRAIN CYCLE OF OPERATION WITHOUT THE BEING BLOCKED BY FLUID FLOW FROM SAID FLUID CIRCULATING MEANS. 